1. Field of the Invention
The present invention relates to a cleaning device, a cleaning method, and an image forming apparatus.
2. Description of the Related Art
Commonly-used image forming apparatuses, such as a copier, a printer, a facsimile machine, and a printer, includes a detachable process cartridge. Such a process cartridge includes a latent image carrier, and at least one of a charging device, a developing device, and a cleaning device for forming an image on the latent image carrier.
Because the process cartridge is detachably attached to the main body of an image forming apparatus, it can be replaced with new one if necessary, and its maintenance need not be performed in a confined space inside the main body. A typical process cartridge rotatably supports a photosensitive drum as a latent image carrier, and includes a cleaning blade that removes residual toner from the photosensitive drum.
For example, Japanese Patent No. 3126532 discloses a conventional cleaning device that includes an inlet seal for guiding toner collected by a cleaning blade to a waste-toner container and an end seal for preventing the toner from leaking from the ends of the inlet seal and the cleaning blade. Japanese Patent No. 3245510 discloses another conventional cleaning device that includes an inlet seal provided upstream of a cleaning blade to guide toner to a waste-toner container. The inlet seal prevents toner from spilling out of the container with respect to the longitudinal direction of the cleaning blade.
In the conventional cleaning devices, the sealing member is arranged in such a manner as to be compressed by a photosensitive drum for sealing the gap between the photosensitive drum and the cleaning member, thereby preventing toner leakage. The sealing member also seals a gap at the ends of the cleaning blade and the inlet seal to prevent toner leakage therefrom. Because the thickness of the cleaning blade is about 1.2 millimeters to 2.0 millimeters, toner leakage from the end of the cleaning blade can be avoided simply by attaching the sealing member to the end of the blade. The inlet seal, however, has a thickness of 30 micrometers to 200 micrometers, and toner leakage therefrom cannot be prevented merely by attaching the sealing member to the end of the inlet seal. For this reason, the sealing member is compressed against the photosensitive drum to prevent the toner leakage from the end of the inlet seal.
The photosensitive drum repeats rotating and stopping operations. The highest line pressure acts on the end of the inlet seal when the photosensitive drum is rotating and stops rotating. The inlet seal, which is attached to the cleaning member with double-faced tape, gradually comes off due to the line pressure acting on its end as image forming operation is repeated. This causes toner leakage from the end of the inlet seal.
Such leaked toner may interfere the image forming operation and degrade the image quality. If this is not the case, the toner that is accumulated inside the image forming apparatus may impair the image appearance or cause a dust problem at the time of maintenance.